We are delighted that our initial call has
received enthusiastic responses. In order to facilitate coordination and reduce
duplication of efforts, please check here to
see language families especially in need of exploration and languages already
taken up. You are nevertheless welcome to contact us even if the language of
your interest is already listed there, as more than one person may jointly work
on a language.

Call for
international collaborations

Cross-Linguistic
distribution of Post-focus Compression (PFC) and its historical origin

Yi Xu, University College
London, UK

Bei Wang, Minzu
University of China, China

Szu-wei Chen, National Chung Cheng
University, Taiwan

Background

There is increasing evidence that prosodic focus (also
known as contrastive stress, nuclear accent, nuclear tone or sentence stress)
is realized in many languages not only by increasing F0, duration,
intensity and upper spectral energy on the focused component itself, but also
by compressing the pitch range and intensity of the post-focus components (Chen
et al., 2009; Cooper et al., 1985; Pell, 2001; Xu, 1999,
2005;
Xu
& Xu, 2005). There is also evidence that such post-focus compression
(PFC) is a highly effective perceptual cue for focus (Xu et
al., 2004). PFC has been reported, explicitly or implicitly, for English,
German, Greek, Dutch, Swedish, Japanese, Korean, Finnish, Arabic, Uyghur,
Tibetan, Hindi, Persian, Finnish,and interestingly, Mandarin Chinese (cf. Xu 2011
for a brief review). The case of Mandarin is especially interesting because it
is fully tonal, and has morpho-syntactic means of
marking focus (clefting, as in English). Thus PFC
could to be independent of the tonal and syntactic characteristics of the
language.

The independence of PFC from tone is more clearly seen in
a surprising new finding that it is absent in Taiwanese, a tone language
closely related to Mandarin (Chen
et al., 2009; Pan, 2007; Xu,
Chen & Wang, in press). More unexpectedly, the same study also found
that PFC is absent in Taiwan Mandarin, an official language spoken in Taiwan,
which resembles Beijing Mandarin in many respects. It seems that Taiwan
Mandarin has lost PFC due to close contact with Taiwanese, because pervasive
bilingualism has been a fact of life in Taiwan for several generations. More
interestingly, there is evidence that PFC is also absent in Cantonese, another
southern Chinese language (Gu & Lee, 2007; Wu &
Xu, 2010). Furthermore, evidence is now emerging that many other languages
probably also do not have PFC, see reviews by Zerbian et al. (2010) and Xu
(2011).

Given the new evidence, a natural question is how could
PFC have gotten into a language in the first place? There are at least three
hypotheses: (a) independent genesis
— emerging automatically in the language, (b) horizontal spreading — entering the language through contact
with a PFC language, and (c) vertical
inheritance — passing down from an ancestral language with PFC.

To support the independent
genesis hypothesis, it would be desirable to show that the emergence of PFC
is a case of convergent evolution, just like the development of webbed feet,
fins and streamlined body shape after adopting an underwater life style.
Otherwise, it would be increasingly difficult to explain why so many seemingly
unrelated languages all independently developed PFC, while many other languages
somehow resisted the same pressure.

To support the horizontal
spreading hypothesis, it would be necessary to show that first, each PFC
language, unless it is the direct descendant of the original PFC language, has
been in contact with a PFC language in the past. In the case of Mandarin, this
is quite likely, because historically it was in close contact with Altaic
languages like Mongolian and Manchurian. We now know that at least some Altaic
languages have PFC, including Japanese and Korean (Lee &
Xu, 2010), although, to our knowledge, Mongolian and Manchurian have not
yet been studied for PFC. The second necessary support for the spreading
hypothesis is that there should be evidence of transmission of PFC from one
language to another during contact. So far, however, there has only been
evidence of losing PFC when two languages are in contact through bilingualism
or second language learning (Wu & Chung, 2011; Chen
et al., 2009; Wang et al., 2011).

Vertical inheritance
seems to be the most extreme of the three hypotheses, as it implies that all
PFC languages are descendants of an ancient proto-language in which PFC was
first developed. But if we were to contemplate such a possibility, implausible
as it may currently seem, what could have been this proto-language? HereÕs a
speculation in Xu (2011):

From
the distribution pattern that is currently emerging, the grouping of the PFC
languages seem to be consistent with the hypothetical Nostratic superfamilty,
consisting of the Indo-European, Uralic, Altaic, Afroasiatic,
Dravidian, Kartvelianand
Eskimo-Aleut language families (Bomhard, 2008;
Pedersen, 1931). Their common ancestor, the proto-Nostratic,
could be dated back to the end of the last Ice Age, i.e., 15,000-12,000 BC,
which was probably spoken along the Fertile Crescent (Bomhard,
2008).

One of the strongest evidence for the Nostratic superfamily hypothesis is the farming and
language expansions after the end of the Ice Age as described by Diamond & Bellwood (2003).

The implications of cross-linguistic investigation of PFC
distribution are many:

1.The current view seems to favor the idea that
every language has a unique but constantly changing prosodic system. Both the horizontal spreading and vertical inheritance hypotheses, however,
would suggest that prosodic features are more stable than previously thought
and may remain in a language for a long time.

2.Most linguistic typological patterns, such as
word order and tonality, are found across languages not closely related to each
other (Haspelmath et al., 2005), suggesting multiple
emergences of similar patterns. But a few typological features, such as
phonemic clicks in southern and eastern Africa (Haspelmath
et al., 2005), and lax prosody in question intonation (Rialland,
2009), seem to occur only in genetically or geographically related languages.
Both the spreading and inheritance hypotheses, if supported,
would group PFC with clicks and lax prosody as one of the hard-to-emerge
features.

3.Research on language typology has so far mostly
relied on evidence from vocabulary, syntax and segmental phonology, and data
collection has been mostly non-experimental. The inclusion of prosody and the use of
systematic experimentation would bring unique contributions to the study of language
typology.

4.Typological research so far has mostly relied on
properties that have to be measured in relative terms, e.g., number of shared
words or phonemes, similarity of syntactic structure, etc. PFC, in contrast, is
a singular feature (though with multiple acoustic cues), and the evidence it
offers may be more clear-cut than most other types of evidence.

5.Support for the vertical inheritance hypothesis would imply that Mandarin is a
descendant of an Altaic language, and the characteristics it shares with other
Chinese languages such as tone and much of the vocabulary are probably acquired
through language contact. This scenario would challenge the standard assumption
that all Chinese languages are derived from a single proto-Chinese language (Bodman, 1980).

6.The testing of the vertical inheritance hypothesis may help establish closer links
between linguistics and population genetics. For example, current genetic
evidence suggests that the southern and northern populations in China belong to
very difference branches (Chu et al., 1998), which is inconsistent with the
widely accepted Sino-Tibetan language family. Separating Mandarin as well as
Tibetan, both are shown to have PFC, from the non-PFC southern Chinese
languages, would reduce the discrepancies between linguistic and genetic trees
in China. Similar improvement could be made in other regions as well.

Call for collaborations

The nature of such cross-linguistic research entails that
this must be a collaborative international effort. We therefore call for
interested colleagues who, regardless of what they think of the hypotheses we
have outlined, are keen to find out whether PFC exists in languages of their
own interest, to join us in this collaborative effort. Please contact Yi Xu at
yi.xu@ucl.ac.uk if you are interested.

To facilitate this effort, we have developed experimental
protocols consisting of basic production and perception experimental designs,
highly efficient procedures and software tools for taking accurate acoustic
measurements, and effective analysis procedures for determining the presence/absence
of PFC in a language. Please see the following for methodological highlights.

7.The
script allows users to label the intervals to be analyzed, and then
automatically generates a long list of text files containing measurements such
as time-normalized F0 contours, time values corresponding to the
time-normalize F0 points, duration of labeled intervals, maxf0,
minf0, meanf0, mean intensity, etc.

áPerception
experiments:

1.Stimuli:
Taken from speakers with maximum, minimum and median standard deviation of all
measured F0 samples of the same speaker

2.Number
of stimuli should allow listening subjects to finish within 1 hour